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EXCHANGE 


12  1921 


Further  Studies  on  Phenolic  Hexa- 
methylenetetramine  Compounds 


DISSERTATION 

BY 
MORTIMER  THOMAS  HARVEY,  B.S.,  Ch.E. 


SUBMITTED  IN  PARTIAL  FULFILLMENT  OF  THE  REQUIRE- 
MENT FOR  THE  DEGREE  OF  DOCTOR  OF  PHILOSOPHY, 
IN  THE  FACULTY  OF  PURE  SCIENCE, 
COLUMBIA  UNIVERSITY 


COLUMBIA  UNIVERSITY 

New  York,  N.  Y. 
May  1,  1920 


Further  Studies  on  Phenolic  Hexa- 
methylenetetramine  Compounds 


DISSERTATION 

BY 
MORTIMER  THOMAS  HARVEY,  B.S.,  Ch.E, 


SUBMITTED  IN  PARTIAL  FULFILLMENT  OF  THE  REQUIRE- 
MENT FOR  THE  DEGREE  OF  DOCTOR  OF  PHILOSOPHY, 
IN  THE  FACULTY  OF  PURE  SCIENCE, 
COLUMBIA  UNIVERSITY 


COLUMBIA  UNIVERSITY 

New  York,  N.  Y. 
May  1,  1920 


FURTHER  STUDIES  ON  PHENOLIC  HEXAMETHYLENE- 
TETRAMINE  COMPOUNDS 

The  production  of  resins  or  resinoid  substances  of 
the  Bakelite  type1  by  the  interaction  of  phenols  with 
compounds  containing  an  active  methylene  group 
has,  of  late,  acquired  considerable  importance  in  the 
industry  of  coal-tar  derivatives.  The  increasing  num- 
ber of  applications  of  these  products  in  the  most 
diversified  fields  is  stimulating  research  in  many 
directions.  That  this  industry  was  born  and  de- 
veloped in  the  United  States,  which  to-day  is  still 
the  leader  in  this  branch  of  chemical  industry,  adds 
interest  to  any  subject  of  research  which  directly 
or  indirectly  may  throw  light  on  the  unusually  com- 
plicated chemistry  of  this  subject. 

The  theoretical  interpretation  of  the  different  phases 
of  the  Bakelite  reaction  is  not  by  any  means  an  easy 
one,  and  considerable  additional  research  work  will 
be  required  before  permitting  ourselves  to  do  much 
beyond  guessing  at  what  really  happens.  In-  the 
meantime,  the  careful  study  of  the  formation  of 
intermediate  products  can  render  us  considerable 
help  in  this  subject.  Among  these  intermediate 
products,  the  further  advances  are  amorphous  mix- 
tures which  are  not  amenable  to  the  usual  methods 
of  chemical  purification  or  isolation.  Therefore,  it  is 
more  natural  to  start  first  with  the  intermediates 
which  are  well-defined  crystalline  bodies  of  which 
the  chemical  composition  can  be  determined  by  well- 
established  methods.  The  present  research  work 
was,  therefore,  confined  to  some  of  the  first  phases 
of  the  reaction,  and  more  particularly  to  such  bodies 
as  are  liable  to  form  when  ammonia  is  used  in  the 
process,  either  as  such  or  in  the  shape  of  hexamethylene- 
tetramine. 

In  the  formation  of  these  products  of  the  Bakelite 
type  the  methylene-containing  body  may  be  com- 

1  These  substances  are  also  known  under  other  trade  names,  as  for 
instance,  Condensite,  Resinit,  Sipilite,  Redmanol,  etc. 


^51721 


mercial  formaldehyde  solution — known  as  formalin, 
formol,  etc.  This  commercial  product  is  practically 
a  mixture  of  several  bodies  containing  active  methylene 
groups,  as,  for  instance,  methylal,  formaldehyde,  the 
polymers  of  formaldehyde,  their  hydrates,  etc.  The 
reaction  is  favored  by  the  addition  of  so-called  con- 
densing agents,  or  catalysts — whatever  that  may 
mean.  Acids,  salts,  and  alkalies  have  been  used  for 
this  purpose.  In  some  cases  where  particular  effects 
have  to  be  v  obtained,  ammonia  is  preferable.  If 
ammonia  is  added  to  formaldehyde  or  to  mixtures 
of  phenol  and  formaldehyde,  the  ammonia  disappears 
immediately  and  bec'omes  hexamethylenetetramine: 

N 


CH5 


CH2 


CH, 


N 


CH2 


N 


CH2 
\ 


N 


\      / 

CH2 

so  that  all  these  reactions  wherein  formaldehyde  and 
ammonia  are  used  conjointly  can  be  repeated  by  the 
direct  use  of  hexamethylenetetramine.  But  in  pres- 
ence of  phenol,  the  hexamethylenetetramine  does  not 
remain  as  such.  It  combines  with  the  phenol  in  the 
proportion  of  three  molecules  of  phenol  to  one  molecule 
of  hexamethylenetetramine  and  produces  a  well- 
defined  crystalline  product,  hexamethylenetetramine 
triphenol,  which  has  been  described  by  Moschatos 
and  Tollens.1 

In  1909,  Lebach2  pointed  out  that  whenever  am- 
monia is  used  in  the  Bakelite  reaction,  hexamethyl- 
enetetramine triphenol  is  formed  in  the  first  stages 
of  the  process.  Under  the  action  of  heat,  this  product 
undergoes  a  further  decomposition  and  resinifies, 
emitting  ammonia.3 

Contrary  to  the  results  of  Moschatos  and  Tollens, 
who  were  unable  to  prepare  addition  products  of 

i  Ann.,  272  (1892),  271. 

*  Z.  angew.  Chem.,  22  (1909),  1600;  J.  Soc.  Chem.  Ind.,  32  (1913),  559. 

s  A  resume  of  the  literature  on  this  subject  is  given  by  L.  H.  Baekeland. 
in  "The  Chemical  Constitution  of  Resinous  Phenolic  Condensation  Prod- 
ucts," J.  Ind.  Enz.  Chem.,  8  (1913),  506. 


5  <- 

hexamethylenetetramine  with  any  of  the  three  cresols 
or  with  carvacrol  or  thymol,  Baekeland  had  suc- 
ceeded in  his  laboratory  in  preparing  a  corresponding 
crystalline  cresol  derivative,  but  inasmuch  as  this  work 
had  not  been  carried  out  with  each  one  of  the  com- 
pletely purified  cresols  and  studied  by  itself,  it  seemed 
desirable  that  each  one  of  the  three  homologs  should 
be  studied  separately  as  to  its  individual  behavior. 
This  research  was  also  extended  to  carvacrol  and  the 
results  obtained  thus  far  are  set  forth.  Similar 
compounds  obtained  from  other  phenolic  bodies  are 
now  under  study.  In  the  meantime,  the  observa- 
tions concerning  the  new  cresol  derivatives  are  submitted 
in  the  present  paper. 

The  reason  of  the  non-success  of  Moschatos  and 
Tollens  in  making  the  cresol  derivatives  of  hexamethyl- 
enetetramine is,  mainly,  that  the  isolation  of  these 
substances  is  incomparably  more  difficult  than  in 
the  case  of  phenol.  The  hexamethylenetetramine 
triphenol  forms  rapidly  and  visibly  under  almost 
all  circumstances,  and  crystallizes  very  well  from 
aqueous  solutions  or  even  from  solutions  when  a 
considerable  excess  of  one  of  the  constituents  is  used. 
This  is  not  the  case  with  some  of  the  cresol  derivatives. 
The  temperature  at  which  they  form  lies  in  some 
cases  so  close  to  the  temperature  at  which  they  de- 
compose that  their  formation  is  almost  sure  to  be 
overlooked  if  proper  precautions  are  not  taken. 
Furthermore,  some  of  those  products  have  a  tendency 
to  remain  liquid  in  the  presence  of  an  excess  of  some 
of  the  reacting  products  or  impurities.  That  such 
products  exist  has  been  established  beyond  doubt 
by  the  present  investigation. 

In  this  work  data  were  determined  for  the  relation- 
ship of  certain  of  the  phenolic  condensation  products. 
The  results  are  appended. 

HEXAMETHYLENETETRAMINE    TRIPHENOL 

Moschatos  and  Tollens  made  the  easily  prepared 
hexamethylenetetramine  triphenol  by  mixing  6  g. 
of  a  concentrated  water  solution  of  hexamethylene- 
tetramine with  a  concentrated  solution  containing 
6  g.  of  phenol.  The  product  isolated  had  the  following 
composition: 

Calculated  for  , Found  by  M.  and  T. — » 

C*HitN4.3C«H»OH  1  2     '  3  4 

Per  cent  Per  cent 

C24 68.25  68.49         68.09 

Hio 7.11  7.34  7.44 

N4 13.27  13.65          13.77 


All  the  phenols  do  not  react  with  hexamethylene- 
tetramine  to  form  an  addition  product  in  which  there 
are  one  mole  of  hexamethylenetetramine  and  three 
moles  of  the  phenol.  The  various  groupings  about 
the  benzene  ring  seem  to  determine  the  extent  to 
which  the  addition  takes  place.  The  three  cresols 
whose  structural  formulas  are  nearly  identical  with 
that  of  ordinary  phenol  and  whose  properties  are 
somewhat  similar  to  the  latter  should  form  addition 
compounds  the  same  as  does  phenol. 

HEXAMETHYLENETETRAMINE    DI-W-CRESOL 

The  w-cresol  addition  product  is  the  most  easily 
obtainable.  At  first  ordinary  w-cresol  was  used 
in  both  dilute  and  concentrated  alcoholic  solutions; 
but  the  expected  crystalline  intermediate  addition 
products  did  not  appear.  The  alcoholic  solutions 
were  refluxed  several  hours  and  the  concentrated 
solutions  allowed  to  stand  several  weeks  to  see  if 
the  compound  would  crystallize  out.  No  crystalline 
product  was  obtained  in  this  case.  There  must 
have  been  some  impurity  in  the  cresol  that  hindered 
the  formation,  for  with  cresol  purified  according  to 
Fox  and  Barker1  the  product  crystallized  out  in  40 
min. 

A  mixture  of  315  g.  of  w-cresol  and  136  g.  of  hexa- 
methylenetetramine was  heated  for  an  hour  in  80 
cc.  of  a  60  per  cent  (60  parts  by  volume  of  alcohol  and 
40  parts  by  volume  of  water)  alcoholic  solution. 
Too  much  heating  caused  the  addition  product  to 
decompose  and  pass  over  into  the  noncrystallizing 
resinous  material.  By  withdrawing  portions  of  the 
mixture  from  time  to  time,  and  cooling  slightly,  it 
could  be  observed,  by  the  formation  of  crystals, 
when  the  most  favorable  point  was  reached  before 
resinification  set  in.  On  stopping  the  heating,  crystals 
appeared  even  in  the  hot  solution.  The  crystals  were 
filtered  off  and  pressed  on  a  porous  tile  to  get  rid  of 
the  adhering  sirupy  material.  The  product  was  then 
dissolved  in  hot  95  per  cent  alcohol.  On  cooling, 
long,  fine,  needle-like  crystals  separated  out. 

Analysis  showed  that  the  substance  was  not  formed 
on  a  1 :  3  basis  as  is  the  case  with  the  ordinary  hexa- 
methylenetetramine triphenol,  but  was  an  addition 
product  of  1  mole  of  hexamethylenetetramine  and 
2  moles  of  w-cresol. 

1  J.  Soc.  Chem.  Ind.,  37  (1918),  260. 


7 
Calculated  for  , Found- 


C6Hi2N4.2CeH4OH.CH3      12  3  4               Av. 

Per  cent  Per  cent 

C2o 67.40                67.45     67.23  ...  ...          67.34 

Hsi 7.87                   8.03        7.80  ...  7.96 

N4 15.73        15.59  15.80   15.69 

Hexamethylenetetramine  di-w-cresol  has  not  a 
true  melting  point,  since  when  the  substance  is  held 
at  a  temperature  around  its  point  of  liquefaction, 
90°  C.,  it  undergoes  decomposition,  passing  over 
into  the  irreversible  resinous  stage.  The  compound 
is  very  soluble  in  hot  95  per  cent  alcohol,  the  solu- 
bility increasing  with  the  temperature.  A  charac- 
teristic feature  is  that  when  it  is  placed  in  a  sufficient 
amount  of  water  or  ether  there  is  a  very  decided 
tendency  towards  a  splitting  of  the  product.  In 
water  the  solubility  of  the  hexamethylenetetramine 
shows  up  predominantly,  as  it  is  dissolved  by  the 
water  leaving  insoluble  cresol  as  an  oil.  In  ether 
the  solubility  of  the  w-cresol  predominates,  and  the  com- 
pound breaks  up  leaving  the  insoluble  hexamethyl- 
enetetramine as  a  precipitate.  The  solubility  in 
benzene  is  moderate,  but  increases  with  the  tempera- 
ture. Acetone  has  the  same  effect  on  the  substance 
as  has  ether,  that  is,  breaking  up  the  structure  by  dis- 
solving out  the  soluble  cresol  and  leaving  the  insoluble 
hexamethylenetetramine. 

HEXAMETHYLENETETRAMINE    DI-/>-CRESOL 

Pure  />-cresol  was  first  made  from  />-toluidine. 
When  it  was  found  that  an  addition  product  was 
formed  with  hexamethylenetetramine,  a  larger  quan- 
tity of  the  material  was  made  by  the  method  given 
by  Fox  and  Barker.1 

A  mixture  of  385  g.  of  p-cresol  and  167  g.  of  hexa- 
methylenetetramine in  150  cc.  of  95  per  cent  alcohol 
was  heated  on  a  steam  bath  for  1.5  hrs.  The  same 
precaution  must  be  observed  here  as  in  the  case  of 
the  formation  of  the  w-cresol  compound.  On  allowing 
the  liquid  to  stand  at  room  temperature,  crystals 
separate  out.  The  compound  was  recrystallized  from 
50  per  cent  alcohol. 

The  addition  product  has  no  melting  point,  but 
begins  to  resinify  at  the  temperature  of  liquefaction, 
87.0°  C.  The  .decomposition  is  shown  when  the 
substance  turns  brown  and  partially  resinifies  upon 
heating  in  a  sealed  glass  tube  for  3  hrs.  at  a  temper- 
ature of  90°  to  100°. 

Analysis  shows  that  it  has  the  same  proportion  of 
the  two  constituents  as  the  w-compound,  namely, 

»  Loc.  cit.,  p.  268. 


8 

1     mole     of     hexamethylenetetramine     and     2    moles 
of  ^-cresol. 


Calculated  for  , Found — 


C6Hi2N4.2CeH40H.CHj      1  3  4               Av. 

Per  cent  Per  cent 

C2o 67.40                67.18     67.35  ...  67.27 

H28 7.87                   8.20       8.01  ...  8.10 

N4 15.73                   15.82  15.71        15.76 

The  same  qualitative  solubilities  as  applied  to  the 
w-cresol  product  apply  to  the  ^-cresol  compound. 

HEXAMETHYLENETETRAMINE    MONO-0-CRESOL 

Pure  0-cresol  was  made  according  to  the  method 
of  Fox  and  Barker.1 

A  mixture  of  475  g.  of  0-cresol  and  205  g.  of  hexa- 
methylenetetramine in  100  cc.  of  95  per  cent  alcohol 
was  heated  on  a  water  bath  for  2.5  hrs.  On  allowing 
to  cool  at  room  temperature,  crystals  separated  out. 
These  were  recrystallized  from  95  per  cent  alcohol. 

The  compound  behaves  somewhat  differently  from 
the  p-  and  w-cresol  addition  products,  since  on  heating 
there  was  no  sharp  melting  point  to  the  liquid  stage, 
followed  by  a  final  passing  over  to  the  resinous  ma- 
terial. A  small  portion  seemed  to  soften  on  heating 
and  show  signs  of  melting,  but  most  of  the  substance 
either  sublimed  or  charred. 

Analysis  showed  that  the  proportion  of  hexamethyl- 
enetetramine to  0-cresol  was  1:1. 


Calculated  for  . Found- 


CeHi2N4.C6H40H.CH3  1234 

Per  cent  Per  cent 

Cu 62.90  63.12          63.20 

H2». ..             8.07  8.07            7.94 

N4 22.55  22.74          22.69 

It  was  thought  that  it  might  be  possible  to  isolate 
a  compound  of  0-cresol  which  would  have  the  same 
proportions  of  the  two  constituents  as  have  the  p- 
and  the  w-cresol  intermediates.  The  crystals  of 
hexamethylenetetramine  were  dissolved  directly  in  the 
0-cresol,  and  with  portions  of  this  solution  various  runs 
were  made  in  which  the  time  factor  of  heating  was 
the  variable.  Heating  was  accomplished  on  a  water 
bath,  the  time  varying  from  2  to  10  hrs.  For  the 
runs  with  a  small  amount  of  heating  the  solution 
was  clear,  while  with  the  runs  extending  over  10  hrs. 
the  solution  was  dark  brown,  showing  that  a  reaction 
had  set  in  with  the  formation  of  the  resinous  material. 
After  allowing  the  solutions  to  stand  several  days 
the  crystals  were  filtered  off,  pressed  on  porous  tile, 
and  recrystallized  from  alcohol.  In  all  cases  analysis 

i  Loc.  cit.- 


9 

of  the  crystals  showed  that  the  product  was  a  com- 
pound with  a  1:  1  proportion  of  hexamethylenetetra- 
mine  and  0-cresol. 

Crystals  obtained  after  8  hrs.'  heating  showed  the 
following  composition: 

Calculated  for 

CeHi2N4.C6H40H.CHa  Found 

Per  cent  Per  cent 

Cw 62.90  63.04 

H2« 8.07  8.22 

N4 2255  22.70 

From  this  it  appears  that  there  is  but  one  addition 
product  of  0-cresol  and  hexamethylenetetramine,  and 
that  is  with  one  mole  of  each  of  the  two  constituents 
present. 

HEXAMETHYLENETETRAMINE    HYDROQUINOL 

Moschatos  and  Tollens1  give  for  the  preparation 
of  this  compound  4  g.  of  hexamethylenetetramine 
in  5  g.  of  water  mixed  with  33  g.  of  hydroquinol  in 
4  g.  of  water.  The  product,  purified  by  washing 
with  water  and  with  ether,  and  drying  over  sulfuric 
acid,  analyzed  as  follows: 

Calculated  for  ^Found  by  M.  and  T.— * 

C6HuN4.C«H4(OH)»  1                  2                  3 
Per  cent 

Ci2 57.60  57.20 

Hit 7.20  7.77 

N4 22.40  22.57         22.47 

This  was  checked  up  as  follows:  5  g.  CeH4(OH)2 
in  9  cc.  of  water  were  mixed  with  a  solution  of  6  g. 
of  hexamethylenetetramine  in  10  cc.  of  water.  The 
solution  was  heated  on  a  water  bath  for  30  min.,  then 
allowed  to  stand  over  night.  Crystals  washed  with 
water,  then  ether,  and"  dried  over  sulfuric  acid.  Anal- 
ysis showed: 

Calculated  for 

C6H,jN4.C«H4(OH)2  Found 

Per  cent  Per  cent 

Cu 57.60  57.35 

Hi, 7.20  7.11 

N4 22.40  22.46 

On  heating,  part  of  the  compound  sublimed  and 
part  charred  with  very'  little  melting.  This  behavior 
is  similar  to  that  of  the  hexamethylenetetramine 
0-cresol  compound. 

HEXAMETHYLENETETRAMINE    RESORCINOL 

Moschatos  and  Tollens  formed  the  compound  by 
heating  a  mixture  of  2  g.  of  hexamethylenetetramine 
dissolved  in  3  g.  of  water  and  3  g.  of  resorcinol  dis- 
solved in  3  g.  of  water.  The  composition  of  the 
compound  was  found  by  Moschatos  and  Tollens  to 
be  as  follows: 

i  Ann.,  272    (1892-3),  282 


Calculated  for          , Found  by  M.  and  T. > 

C6HijN4.C6H4(OH)2        1  2     '  3  4 

Per  cent  Per  cent 

Ci2 57.60  57.14         57.35 

Hii 7.20  7.43  7.42 

N4 22.40  ...  ...  22.09         22.32 

By  following  the  same  order  of  procedure  as  outlined 
above,  a  precipitate  was  easily  obtained.  On  analysis 
the  composition  was  found  to  be  the  same  as  that 
represented  by  Moschatos  and  Tollens: 

Calculated  Found 

Per  cent  Per  cent 

Ci2 57.60  57.39 

Hii 7.20  7.10 

N4 22.40  22.34 

This  compound  also  shows  no  melting  point,  which 
is  similar  to  the  hydroquinol  and  the  0-cresol  inter- 
mediates. It  seems  to  be  a  characteristic  feature  of 
the  hitherto  observed  phenol  hexamethylenetetramine 
compounds  that  it  is  necessary  that  there  be  at  least 
2  moles  of  the  phenol  to  1  of  the  hexamethylene- 
tetramine in  order  that  there  be  a  well-defined  point 
of  liquefaction. 

HEXAMETHYLENETETRAMINE    CARVACROL 

The  carvacrol  obtained  for  use  in  this  work  was 
made  from  cymene.1  It  ran  93  per  cent  pure,  the 
other  constituents  being  approximately  6  per  cent 
thymol  and  1  per  cent  thiophenols.  The  product 
was  purified  according  to  the  method  developed  by 
Mr.  Allan  Leerburger: 

A  very  stiff  paste  of  the  carvacrol  and  lead  acetate  was  al- 
lowed to  stand  at  room  temperature  for  30  hrs.  The  mass 
was  broken  up  and  the  phenols  extracted  with  petroleum  ether. 
The  carvacrol -lead  acetate  compound  is  soluble  in  the  petroleum 
ether,  whereas  the  thymol-lead  acetate  is  insoluble  in  the  ether, 
giving  a  means  of  separating  the  two  phenols.  After  allowing 
the  petroleum  ether  to  evaporate,  the  liquid  was  washed  with 
a  normal  solution  of  mercuric  chloride  (using  as  the  solvent 
50  parts  by  volume  of  water  and  50  parts  by  volume  of  alcohol). 
This  removes  the  thiophenols,  leaving  the  carvacrol  as  the  oil. 
The  carvacrol  then  distilled  in  a  4-bulb  fractionating  column, 
the  portion  boiling  between  237°  and  239°  C.  being  taken. 

One  mole  of  hexamethylenetetramine  in  just  suffi 
cient  95  per  cent  alcohol  to  dissolve  the  crystals  was 
mixed  with  3  moles  of  the  purified  carvacrol.  The 
mixture  was  heated  on  a  water  bath  for  40  hrs.,  then 
allowed  to  sta,nd  at  room  temperature  for  1  wk. 
The  uncrystallized  mass  was  dissolved  out  by  mixing 
with  kerosene.  The  fine  precipitate  was  filtered, 
and  the  crystals  dissolved  in  hot  95  per  cent  alcohol. 

i  Hixson  and  McKee,  J.  Ind.  Eng.  Chem.,  10  (1918),  982 


On  cooling  the  alcoholic  solution  the  compound 
crystallized  out  readily.  Further  purification  was 
made  by  repeating  the  crystallization  from  hot  95 
per  cent  alcohol. 

The  compound  shows  a  point  of  liquefaction  at 
148°  C.,  at  which  point  it  resinifies  quickly.  It  is 
very  soluble  in  hot  95  per  cent  alcohol,  but  insoluble 
in  the  cold  alcohol.  An  important  point  is  that  it  is 
very  soluble  in  ether  and  acetone.  Some  of  the 
cresol  compounds,  as  has  been  stated,  may  be  broken 
up  in  water,  ether,  and  acetone,  the  two  latter  sol- 
vents dissolving  out  the  easily  soluble  cresols  and 
leaving  the  insoluble  hexamethylenetetramine  as  a 
precipitate.  This  difference  in  solubility  between 
the  carvacrol  and  cresol  compounds  may  be  due  to 
the  difference  in  linkings  of  different  phenols  with  the 
hexamethylenetetramine. 

Analysis  showed  that  the  compound  was  not  of 
the  same  order  of  addition  as  were  cresol  and  phenol 
products,  which  were  in  the  proportion  of  1  mole 
of  hexamethylenetetramine  to  2  moles  of  the  m- 
or  ^-cresol,  and  3  moles  of  phenol  to  1  mole  of  hexa- 
methylenetetramine. The  composition  was  found  to 
be  as  follows: 

Run  1  Run  2  Average 

Per  cent  Per  cent  Per  cent 

Carbon 76.95  77.10  77.02 

Hydrogen 9.20  9.27  9.23 

Nitrogen 4.92  4.99  4.96 

From  the  table  below  it  is  clearly  seen  that  the 
hexamethylenetetramine  is  not  directly  added  to  the 
carvacrol  as  it  is  in  the  case  of  the  cresols  and  phenols. 

C6Hi2N4.CioHi4O  C6Hi2N4.2CioHi4O  C6Hi2N4.3CioH14O  Found 

Carbon 66.25                        71.00                              73.25  77.02 

Nitrogen 19.35                       12.75                               9.50  4.96 

Hydrogen 8.96                        9.10                               9.16  9.23 

The  percentages  found  do  not  correspond  to  any 
simple  proportion  of  addition,  as  was  shown  in  the 
case  of  the  other  phenols  mentioned.  However, 
if  we  assume  that  a  nitrogen  is  broken  out  of  the 
structure  of  the  hexamethylenetetramine  to  form  am- 
monia with  hydrogens  of  the  hydroxyls  of  3  moles  of 
carvacrol,  and  further  that  2  moles  are  taken  up 
additively  by  one  or  two  of  the  other  nitrogens,  the 
percentages  of  carbon,  hydrogen,  and  nitrogen  corre- 
spond exactly  with  the  percentages  as  found.  The 
smell  of  ammonia  toward  the  end  of  the  heating  in 
the  formation  of  this  compound  seems  to  bear  out 
this  point  that  ammonia  is  split  out,  but  no  quan- 
titative determination  has  thus  far  been  undertaken. 
The  diagrams,  in  which  R  represents  the  radical 


part    of    the    carvacrol    structure,    illustrate    possible 
arrangements. 

H 

N— OR 
^_CH2-OR  ^/  j\CH2_OR 

CH2      CH2  or         CH2      CH2 

/I  I  \ 

ROH— N-CH2— N— CH2— OR     RO— N— CH2— N— CH2— OR 

/  \  l\ 

ROH  CHz— OR  H     CH2— OR 

It  is  to  be  pointed  out  that  although  the  interpreta- 
tion of  the  structure  of  hexamethylenetetramine  is 
thus  far  rather  arbitrary,  and  although  the  correct 
one  may  be  found  to  be  quite  different  from  the  above, 
the  percentages  of  elements  will  in  all  cases  be  the 
same  for  the  theoretical  carvacrol  compound. 

Calculated  from 

Above  Structure  Found  Deviation 

Per  cent  Per  cent  Per  cent 

Carbon 76.95  77.02  0.07 

Nitrogen 4.84                     4.96  0.12 

Hydrogen 9.10                     9.23  0.13 

All  this  becomes  rather  easy  of  interpretation  if  in 
the  formation  of  the  hexamethylenetetramine  car- 
vacrol compound  there  has  been  1  mole  of  ammonia 
split  out  and  there  have  been  2  moles  of  carvacrol 
added  to  one  of  the  nitrogen. 

ENERGY    RELATIONSHIP    OF    PHENOLIC    HEXAMETHYLENE 
COMPOUNDS 

APPARATUS — For  the  heat  of  combustion  of  the 
phenol,  hexamethyienetetramine,  and  hexamethylene- 
tetramine triphenol,  an  Emerson  adiabatic  bomb 
calorimeter  provided  with  a  proper  stirrer  and  a 
Beckmann  thermometer  graduated  to  give  an  estimated 
reading  of  0.001°  were  used  For  the  heat  of  solution 
the  bomb  was  eliminated  and  the  metal  can  for  the 
water  replaced  by  a  glass  container.  The  substance 
whose  heat  was  to  be  determined  was  held  in  a  glass- 
stoppered  weighing  bottle,  the  cover  of  which  was 
removed  by  small  wires  passing  through  the  third 
hole  in  the  top  of  the  calorimeter  jacket. 

DATA — The  water  equivalent  of  the  calorimeter 
was  determined  in  the  ordinary  way  by  burning  a 
material  whose  heat  of  combustion  was  known.  Naph- 
thalene from  the  U.  S.  Bureau  of  Standards  laboratory 
was  used.  By  weighing  the  separate  parts  of  the 
bomb  and  accessories,  the  water  equivalent  of  the 
bomb  was  found  to  be  453  g.;  without  the  bomb  it  was 
found  to  be  70  g.  The  error  in  the  first  number  was 


13 

±2  g.,  and  that  in  the  second  number  was  =*=5  g. 
Checking  these  values  against  other  standard  sub- 
stances, 6320  was  obtained  for  benzoic  acid,  whereas 
the  Bureau  of  Standards  gives  6329  cal.  per  g.  as  the 
correct  result.  The  second  value  was  used  in  finding 
the  heat  of  solution  of  as  pure  sodium  hydroxide  as 
could  be  made  without  wasting  too  much  time.  The 
following  shows  a  comparison  of  the  heat  of  solution 
of  sodium  hydroxide  as  determined  by  Thomsen,  and 
by  Berthelot,  and  as  obtained  in  this  study: 

Kg.  Cal. 

Thomsen 9.94 

Berthelot 9.78 

Present  work 9.85 

The  errors  here  would  seem  to  be  due  to  the  varied 
purity  of  the  NaOH  used,  rather  than  to  the  manipu- 
lation of  the  apparatus. 

(«)   Heat  of  solution  of  hexamethylenetetramine. 

Kg.  Cal. 

Run  1  4.902 

Run  2  4.896 

AVERAGE        4.8991        (where  1  Cal.  -   1000  small  calories) 
1  Delepine  (Bull.,   [3]   15,     1200)   gives  the  heat  of  solution  of  hexa- 
methylenetetramine at  15°  C.  as  4.8  Cal. 

(ft)    Heat  of  solution  of  phenol. 

Kg.  Cal. 

Run  1  —2.92 

Run  2  —2.87 


AVERAGE         — 2 . 89 l 

1  Landolt  and  Bornstein,  3rd  Ed.,  p.  419,  give  for  the  heat  of  solution 
of  phenol  —2.6  Cal. 

(c)  Heat  of  reaction  of  phenol  and  hexamethylene- 
tetramine in  an  aqueous  solution — In  this  observation 
the  phenol  was  first  added  to  the  water,  then  solid 
hexamethylenetetramine  added  in  the  manner  stated 
above.  The  excess  of  rise  of  temperature  above  that 
given  by  the  hexamethylenetetramine  would  be  due 
to  the  reaction  of  the  amine  and  the  phenol.  This 
is  the  weak  point  of  this  method  of  determining  the 
heat  of  formation  of  hexamethylenetetramine  tri- 
phenol,  since  it  is  difficult  to  obtain  accurately  the 
amounts  j>f  amine  and  phenol  that  have  combined 
in  solution.  After  the  reaction  the  hexamethylene- 
tetramine solution  was  distilled  to  obtain  the  phenol, 
the  amount  of  which  was  determined  by  the  tribromo- 
phenol  method.1  The  error  in  this  way  would  be  in 
the  dissociation  of  the  triphenol  compound  on  dis- 

»  AMen's  "Commercial  Organic  Analysis,"  8th  Ed.,  Vol.  3,  p.  307. 


tillation  of  the  phenol.     It  was  found  that  the  energy 
reaction  was 

(CH2)6N4Aq.  +  3C6H6OAq.  =  (CH^elNkSCeHeO.Aq.  +  3.739  Cal. 
(d)   Heat  of  formation  of  hexamethylenetetramine. 

Heat  of  combustion  of  commercial  hexamethylenetetramine: 

Run  1 — 7 . 380  Cal.  per  g.  at  constant  volume 

Heat  of  combustion  of  hexamethylenetetramine  resublimed  in  labora- 
tory: 

Run  2  7.397  Cal.  per  g.  at  constant  volume 

Run  3  7.399 


AVBRAGB        7 . 398 

By  means  of  the  Hempel  gas  apparatus  and  freshly 
prepared  solutions  of  sodium  hydroxide  and  pyrogallol, 
the  following  results  on  the  products  of  combustion 
were  obtained: 

Actual  Result         Theoretical  Result 
PRODUCTS  Grams  Grams 

N2 0.40  0.38 

HNOj 0.119  0.112 

C0» 1.80  1.88 

To  represent  the  above  results  we  can  write  the  equation 

(CH2)CN4  +  18.55(0)  =  6C02  = 

5.89H2O  +  1.89N2  +  0.22  HNO3  +  1036.9  Cal. 

We  know  that 

6(C)  +  12(0)  =  6C02  +  6  X  96.98  Cal.  (1) 

(Land,  and  Born.,  4th  Ed.,   p.  855) 
11.78(H)  +  5.89(0)  =  5.89H2O  +  68.357  X  5.89  Cal.         (2) 

(Land,  and  Born.,  4th  Ed.,  p.  850) 
0.22(H)  -f-  0.22(N)  -f  0.66(O)  =  0.22HNO3  +  41.60  Cal.  (3) 

(Land,  and  Born.,  4th  Ed.,  p.  854) 

Substituting  these  three  equations  in  the  found  equa- 
tion above,  we  have: 

6(C)  +  12(H)  +4(N)  =  (CH2)eN4  —  43.18  Cal. 
Therefore   the   heat   of   formation   of   hexamethylene- 
tetramine =  — 43.18  Cal. 

(e)  Heat  of  formation  of  phenol — Berthelot1  gives 
the  heat  of  combustion  of  phenol  at  constant  pressure 
and  18°  C.  as  736.00  Cal.  per  mole. 

Required:  6(C)  +  6(H)  +  (O)  =  C6H6O  +  x  Cal. 
Found:   C6H6O  +  14(O)  =  60  O2    +  3H2O  +  736.00  Cal. 
We  know  that: 

6(C)  +  12(0)  =  60  02  +  96.98  Cal.        *  (1) 

3H2  +  30  =  3H2O  +  68.36  X  3  Cal.  (2) 

Substituting   Equations   1   and  2  in  the  found  equa- 
tion we  obtain 

6(C)  +  6(H)  +  O  =  C6H6O  +  50.96  Cal. 
Accordingly  the  heat  of  formation  of  phenol  is  50.96 

i  Ann.  chim.  phys.,  [6]  3  (1888),  326. 


15 

Cal.  per  mole.  This  value  is  different  from  the  one 
Berthelot  gives1  because  he  uses  the  heat  of  formation 
of  C02  as  94.30  Cal.  and  the  heat  of  formation  of 
water  as  69.00  Cal.  These  values  are  not  considered 
correct  and  better  values  are  used  in  the  calculations 
above.2  The  value  736.00  Cal.  per  mole  for  the  heat 
of  combustion  of  phenol  is  used  here  because  it  repre- 
sents the  value  obtained  in  this  research. 

(/)   Heat    of   solution    of   hexamethylenetetramine    tri- 
phenol. 

Average  value  obtained  was — 10.671  kg.  Cal. 

(g)   Heat  of  formation  of  hexamethylenetetramine  tri- 
phenol. 

The  heat  of  combustion  of  hexamethylenetetramine 
triphenol  at  constant  pressure  was  found  to  be  3228.30 
Cal.  per  mole. 
Required:  24(C)  +  30(H)  +  3(O)  +  4(N)  = 

(CH2)6N4.3CGH6O  +  x  Cal. 
Found:  (CH2)6N4.3C6H6O  -f  30.73(O)  = 

24CO2  +  14.71H20  +  1.71N2  +  0.58HNO3  -f  3228.30  Cal. 

We  know: 

24(C)  -f-  48(0)  =  24(CO2)  +  96.98  X  24  Cal.  (1) 

29.42(H)  +  14.71(0)  =  14.71H2O  +  68.357  X  14.71  Cal.  (2) 
0.58(H)  +  0.58(N)  +  1.74(O)  = 

58  HN03  +  41.60  X  0.58  Cal.    (3) 

Substituting  these  three  equations  in  the  above  found 
equation  and  solving,  we  obtain  the  required  equation : 

24(C)  4-  30(H)  +  3(0)  +  4(N)  = 

(CH2)cN4.3C6H60  4-  128.76  Cal.  per  mole 

The  heat  of  formation  of    hexamethylenetetramine 
triphenol,  starting  with  crystals  of  phenol  and  amine, 
is  as  follows: 
Required:  Hexamethylenetetramine  +  3  phenol  = 

H.T.P.  4-  x  Cal. 

or  (CH2)6N4(crys.)  +  3C6H6O(crys.)  = 

(CH,)6N4.3C6H6O(crys.)  X  Cal. 

We  know: 

6(C)  +  12(H)  +  4(N)  =  (CH2)CN4  —  43.18  Cal.  (1) 
18(C)  +  18(H)  +  3(0)  =  3C6H60  +  3  X  50.96  Cal.  (2) 
24 (C)  +  30(H)  +  3(0)  -f  4(N)  = 

(CH2)6N4.3C6H6O  +  128.76  Cal.        (3) 

Subtracting  (1)  and  (2)  from  (3)  we  obtain: 

(CH2)6N43C6H6O  =  (CH2)6N4.3C6H6O  -f  19.06  Cal. 

1  Vol.  2,  p.  818. 

2  Landolt  and  Bornstein,  4th  Kd.,  p.  855. 


1 6 

(//.)    Heat    of    combustion     of    hexamethyltneietramine 
di-p-cresol. 

AT  CONSTANT  VOLUME,  20°  C. 

Cal.  per  G. 
Run  1  8.024 

Run  2  7.992 


AVERAGE       8.008 

(i)  Heat  of  combustion  of  hexamethylenetetramint 
di-m^-cresoL 

At  constant  volume  and  20°  C.  =  8.010  Cal.  per  gram 

(j)  Heat  of  combustion  of  hexamethylenetetramine 
mono-resorcinol. 

AT  CONSTANT  VOLUME  AND  20°  C. 

Cal.  per  G.     * 
Run  1  6.730 

Run  2  6 . 700 

AVERAGE       6.715 

In  the  addition  reactions  of  hexamethylenetetra- 
mine  with  a  phenol  thus  far  investigated  there  does 
not  seem  to  be  any  definite  rule  by  which  one  is  en- 
abled to  determine  the  number  of  moles  of  phenol 
that  will  combine  with  the  hexamethylenetetramine. 

Falk  and  Nelson1  have  assumed  that  in  catalytic 
reactions  there  are  binary  and  ternary  compounds 
formed.  Kendall2  has  called  attention  to  the  impor- 
tant general  rule  that  stable  addition  compounds 
are  formed  when  there  is  a  marked  chemical  con- 
trast (acidic  and  basic)  between  the  two  reacting 
components.  Thus  in  the  additive  compound  formed 
between  organic  acids  and  phenols,  the  stability  is 
very  much  greater  when  the  organic  acid  is  strong 
and  the  phenol  weak,  or  vice  versa,  than  in  the  case 
in  which  both  substances  exhibit  the  same  degree  of 
acidity.  A  similar  generalization  holds  for  the  addi- 
tion compounds  between  two  acids,  or  between  an 
acid  and  a  ketone,  or  an  acid  and  an  aldehyde. 

In  the  case  of  the  addition  compounds  formed  in 
this  work  we  have  the  phenol  acting  as  the  acid  and 
the  hexamethylenetetramine  as  the  base.  It  might 
be  assumed  from  this  and  from  Kendall's  generaliza- 
tion that  the  greater  the  chemical  conratst  the  greater 
the  stability  of  the  compounds  formed,  and  the  greater 
the  number  of  moles  of  phenol  combining  with  the 
basic  hexamethylenetetramine.  This  is  not  the  case, 
however,  in  this  instance.  The  degree  of  acidity 
seems  to  have  very  little  to  do  with  the  extent  of  the 

1  J.  Am.  Chem.  Soc.,  37  (1915),  1723. 
*lbid.,  36  (1914),  2498. 


I? 

reaction.  Ordinary  phenol,  which  is  a  weaker  acid 
than  0-cresol,  combines  in  the  proportion  of  three 
moles  of  phenol  to  one  of  hexamethylenetetramine, 
whereas  the  cresol  combines  in  the  proportion  of 
1:1.  Nitric  acid,  a  very  strong  acid  in  comparison 
with  the  phenol,  combines  only  in  .the  proportion  of 
1  mole  of  hexamethylenetetramine  to  2  moles  of 
acid.  Hence  we  cannot  apply  the  generalization 
stated  above  to  the  case  of  phenol  addition  products. 
Again,  the  three  cresols  have  practically  the  same 
order  of  hydrogen-ion  concentration,1  but  with  the 
p-  and  w-compounds  there  are  2  moles  adding, 
whereas  with  the  0-cresol  there  is  only  1  mole  adding 
to  the  hexamethylenetetramine. 

Since  the  activity  of  phenol  is  greatly  diminished 
in  the  case  of  the  cresols,  by  the  presence  of  a  methyl 
group,  it  might  be  said  that  the  more  negative  the 
benzene  ring  is  made  with  negative  groups  (nitro 
and  hydroxy)  the  greater  the  activity  and  the  greater 
the  number  of  moles  uniting.  With  hydroquinol 
and  resorcinol,  where  there  are  two  hydroxy  groups, 
the  opposite  is  true.  They  react  slowly  with  hexa- 
methylenetetramine, and  then  only  in  the  proportion 
of  one  mole  of  the  phenol  to  one  of  the  amine.  Picric 
acid,  which  contains  three  nitro  groups  and  one 
hydroxy  group,  should  represent  a  substance  in  which 
the  benzene "  ring  has  practically  the  maximum  of 
negative  groups,  and  hence  should  have  high  combining 
properties.  Moschatos  and  Tollens  found  that  the 
proportion  was  only  1:1.  As  yet  no  rule  can  be 
laid  down  connectin-g  the  acidity,  or  the  degree  to 
which  the  benzene  ring  is  made  negative  by  negative 
groupings,  with  the  additive  properties  of  phenols 
and  hexamethylenetetramine. 

Why  should  two  moles  of  p-  and  w-cresol  unite 
with  one  mole  of  hexamethylenetetramine.  while  only 
one  mole  of  0-cresol  unites  with  one  mole  of  amine? 
One  difference  lies  in  the  structure  assumed  for  the 
three  cresols.  The  hydroxy  group  of  the  p-  and  m- 
cresols  has  on  each  side  of  it  a  hydrogen,  while  the 
hydroxy  group  of  0-cresol  has  a  hydrogen  on  but  one 
side.  From  this  it  would  seem  that  the  extent  of 
addition  depends  upon  the  number  and  activity  of 
the  hydrogens  adjacent  to  the  reacting  hydroxy  group. 

The  structure  of  hexamethylenetetramine  as  given  by 
does  not  seem  to  represent  all  the  facts  as  presented 

1  Scudder,  "Conductivity  and  lonization  Constants." 


i8 


N 
\ 

CH2       CH2 


N 


CH2 


N 
\ 


CH2 


\ 


\      / 
CH2 

by  the  addition  products  with  phenols.  Here  the 
four  nitrogens  are  all  tertiary  in  character  and  we 
should  expect  that  hexamethylenetetramine  would 
add  four  moles  of  an  alkyl  halide.  A.  Wohl1  found 
that  but  one  mole  of  methyl  iodide  was  taken  up 
additively.  In  all  the  phenol  addition  compounds 
that  have  been  isolated  there  is  not  one  case  where 
the  number  of  moles  of  phenol  combining  with  one 
mole  of  hexamethylenetetramine  is  greater  than 
three.  In  the  carvacrol  compound  found  in  this 
investigation  there  is  strong  evidence  that  one 
nitrogen  is  more  reactive  than  the  others.  This  is 
shown  by  the  fact  that  ammonia  has  been  split  out 
with  one  of  the  nitrogens  before  one  of  the  other 
three  has  added  any  phenol. 

Hexamethylenetetramine  is  formed  from  ammonia 
and  formaldehyde.  Tertiary  amines  are  formed  from 
ammonia  and  an  alcohol.  Alcohol  is  a  lower  oxida- 
tion product  than  is  the  aldehyde.  Again,  amides 
are  formed  from  ammonia  and  an  acid,  the  latter  being 
of  a  higher  oxidation  than  the  aldehyde.  From  this 
we  might  expect  that  hexamethylenetetramine  should 
not  be  represented  wholly  as  a  tertiary  amine,  but 
should  exhibit  a  character  midway  between  the  tertiary 
amine  and  an  amide. 

It  does  not  seem  from  these  considerations  that  the 
structure  of  hexamethylenetetramine  is  properly  repre- 
sented when  written  in  the  above  manner. 

This  work  was  undertaken  at  the  suggestion  and 
under  the  guidance  of  Professor  L.  H.  Baekeland.  I 
beg  to  express  my  thanks  to  him  and  to  Professors 
Thomas  B.  Rreas,  J.  M.  Nelson,  and  Ralph  McKee, 
for  their  valuable  advice. 

i  Ber.,  19  (1886),  1840 


VITA 

Mortimer  Thomas  Harvey  w.as  born  August  21, 
1895,  at  New  York  City,  and  received  his  elementary 
education  in  the  Public  School  and  High  School  at 
Ticonderoga,  New  York. 

He  attended  Union  College  from  September  1913 
to  June  1917,  receiving  the  degree  of  Bachelor  of 
Science  in  Sanitary  Engineering. 

He  studied  at  Columbia  under  the  Department  of 
Chemical  Engineering  from  September  1917  to  June 
1920.  In  February  1920  he  received  from  Columbia 
University  the  degree  of  Chemical  Engineer. 

During  1918  and  1919  he  was  assistant  in  the  Chem- 
ical Engineering  laboratory  at  Columbia  University. 

During  1919  and  1920  he  held  the  Research  Fellow- 
ship of  the  General  Bakelite  Company. 


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WILL  INCREASE  TO  SO  CENTS  ON  THE  FOURTH 
DAY  AND  TO  $1.OO  ON  THE  SEVENTH  DAY 
OVERDUE. 


SEP  28  1933 


SEP  29  1333 

OCT   1M933 

Jin 

JVL  12  1935 

LD  21-100m-7,'33 

451721 


UNIVERSITY  OF  CALIFORNIA  LIBRARY 


